Neutron capture therapy system

ABSTRACT

A neutron capture therapy system includes a neutron beam generating unit, an irradiation room configured to irradiate an irradiated body with a neutron beam, a preparation room configured to implement preparation work required to irradiate the irradiated body with the neutron beam, and an auxiliary positioner disposed in the irradiation room and/or the preparation room. The irradiation room includes a first shielding wall, a collimator is disposed on the first shielding wall for emitting the neutron beam, the neutron beam is emitted from the collimator and defines a neutron beam axis. The auxiliary positioner includes a laser emitter that emits a laser beam to position the irradiated body. Wherein the position of the laser emitter is selectable. Therefore, the irradiated body can be positioned in any case to implement precise irradiation.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 16/880,125, filed on May 21, 2020, now allowed,which itself is a continuation application of International ApplicationNo. PCT/CN2018/100987, filed on Aug. 17, 2018, which claims priority toChinese Patent Application No. 201711365076.4, filed on Dec. 18, 2017,and Chinese Patent Application No. 201721777784.4, filed on Dec. 18,2017, the disclosures of which are hereby incorporated by reference intheir entireties.

FIELD

The present disclosure relates to a radioactive irradiation system, andmore particularly to a neutron capture therapy system.

BACKGROUND

The background description provided herein is for the purpose ofgenerally presenting the context of the disclosure. Work of thepresently named inventors, to the extent it is described in thisbackground section, as well as aspects of the description that may nototherwise qualify as prior art at the time of filing, are neitherexpressly nor impliedly admitted as prior art against the presentdisclosure.

As atomics moves ahead, radiotherapy such as Cobalt-60 therapy, linearaccelerator therapy and electron beam therapy has been one of the majorapproaches to cancer treatment. However, conventional photon or electrontherapy has been undergone physical restrictions of radioactive rays.For example, a large amount of normal tissues on a beam path will bedamaged as tumor cells are killed. Moreover, tumor cells have differentradiosensitivity, and as a result conventional radiotherapy falls shortof treatment effectiveness on radioresistant malignant tumors (such asglioblastoma multiforme and melanoma).

To reduce radiation-induced damage to the normal tissue around thetumor, targeted therapy in chemotherapy has been applied toradiotherapy. For high-radioresistant tumor cells, proton therapy, heavyparticle therapy, neutron capture therapy, and the like using aradiation source with high relative biological effectiveness (RBE) arebeing actively developed at present. The neutron capture therapycombines the target therapy with the RBE. For example, the boron neutroncapture therapy (BNCT). By virtue of specific grouping ofboron-containing drugs in the tumor cells and precise neutron beamirradiation to provide a better cancer treatment option thanconventional radiotherapy.

To implement precise neutron beam irradiation, in a preparation room, itis necessary to precisely position and mark the tumor position of apatient through CT imaging and the like and a laser positioning system.In an irradiation room, it is necessary to position the patient throughthe laser positioning system and the mark made in the preparation roomto enable a neutron beam to aim the tumor for irradiation. Aconventional laser positioning system includes four laser emittersfixedly installed on the walls and ceilings of the preparation room andthe irradiation room, respectively. Because the laser emitters arefixed, when an infusion tube, a treatment bed, and other objects in thepreparation room and/or the irradiation room block a laser beam, it isdifficult to implement precise positioning of the patient, and as aresult precise neutron beam radiotherapy cannot be implemented.

SUMMARY

To resolve the foregoing problem, one aspect of the present disclosureprovides a neutron capture therapy system. The neutron capture therapysystem includes an irradiation room configured to irradiate anirradiated body with a neutron beam, a preparation room configured toimplement preparation work required to irradiate the irradiated bodywith the neutron beam, and an auxiliary positioner disposed in theirradiation room and/or the preparation room. The irradiation roomincludes a first shielding wall and a collimator disposed on the firstshielding wall for emitting the neutron beam, and wherein the neutronbeam is emitted from the collimator and defines a neutron beam axis. Theauxiliary positioner includes a laser emitter for emitting a laser beamto position the irradiated body, and wherein a position of the laseremitter is selectable.

Compared with the prior art, the technical solution recorded in thisembodiment has the following beneficial effects: The position of thelaser emitter is selectable. Therefore, the irradiated body can bepositioned in any case to implement precise irradiation.

Preferably, the auxiliary positioner includes a base and a cantileverextending perpendicularly from the base, and the laser emitter isdisposed on the cantilever.

Further, the cantilever is provided with a guiderail for guiding thelaser emitter to move and a positioning member for fixing the laseremitter at a predetermined position.

Preferably, the cantilever is telescopic.

Preferably, a plurality of laser emitters are disposed, and a pluralityof laser emitters are sequentially arranged from a position close to anend, away from the base, of the cantilever.

Preferably, the preparation room includes a first wall provided with acollimator model having a same structure and size as the collimator, andthe auxiliary positioner is disposed around the collimator and/or thecollimator model and installed on the first shielding wall and/or thefirst wall.

Preferably, the preparation room includes a first wall provided with acollimator model having a same structure and size as the collimator, andthe auxiliary positioner is installed on the collimator and/or thecollimator model.

Preferably, the neutron capture therapy system further comprising aneutron beam generating unit for generating the neutron beam, whereinthe neutron beam generating unit includes an accelerator configured toaccelerate a charged particle beam, a neutron beam generator reactingwith the charged particle beam to generate the neutron beam, and acharged particle beam transmitter located between the accelerator andthe neutron beam generator and configured to transmit the chargedparticle beam.

Preferably, the base and the cantilever are both rectangular cuboids,the first shielding wall and the first wall are respectively providedwith a fixing portion and a positioning portion which are respectivelydisposed around the collimator and the collimator model and adapted tofix the auxiliary positioner, wherein the neutron capture therapy systemdefines XYZ coordinates including a Y-axis parallel to the neutron beamaxis, a Z-axis perpendicular to a ground, and an X-axis orthogonal tothe Y-axis and the Z-axis, the fixing portion includes a first fixingportion located right above the collimator and arranged in parallel tothe X-axis, a second fixing portion located on a left side of thecollimator and arranged in parallel to the Z-axis, and a third fixingportion located on a right side of the collimator and arranged parallelto the Z-axis direction, the positioning portion includes a firstpositioning portion, a second positioning portion, and a thirdpositioning portion respectively disposed corresponding to the firstfixing portion, the second fixing portion, and the third fixing portion,the structures and sizes of the first fixing portion, the second fixingportion, and the third fixing portion are respectively the same as thoseof the first positioning portion, the second positioning portion, andthe third positioning portion, when a center of a projection of thecollimator on the first shielding wall and a center of a projection ofthe collimator model on the first wall are respectively as adapted to bereference points, coordinate values of a center of the first fixingportion, the second fixing portion and the third fixing portion arerespectively the same as coordinate values of a center of the firstpositioning portion, the second positioning portion and the thirdpositioning portion.

Preferably, the base is a hollow cylinder, the cantilever is ahexahedron disposed perpendicular to the base, the first shielding walland the first wall are respectively provided with a fixing portion and apositioning portion for fixing the auxiliary positioner, wherein theneutron capture therapy system defines XYZ coordinates including aY-axis parallel to the neutron beam axis, a Z-axis perpendicular to aground, and an X-axis orthogonal to the Y-axis and the Z-axis, and thefixing portion and the positioning portion are hollow circular ringshaving an identical size and a center of a circle respectively the sameas a center of a projection of the collimator on the first shieldingwall and a center of a projection of the collimator model on the firstwall.

Preferably, the base is provided with an annular track on which thecantilever slides in a circumferential direction and a fastening memberfor fixing the cantilever at a predetermined position, and thecantilever is provided with a guiding portion fitting with the annulartrack and a clamping member fitting with the fastening member to fix thecantilever.

Preferably, the base is detachably mounted on the first shielding walland/or the first wall.

Preferably, the base is detachably mounted on the collimator and/or thecollimator model.

In another aspect of the present disclosure provides neutron capturetherapy system, the neutron capture therapy system includes airradiation room provided with a collimator for a neutron beam to beemitted, a preparation room provided with a collimator model having asame structure and size as the collimator, and an auxiliary positionerdisposed in the irradiation room and/or the preparation room, whereinthe auxiliary positioner includes a base and a cantilever extending fromthe base. The cantilever is provided with at least one laser emitter foremitting a laser beam. A position of the laser emitter is selectable,and a relative position between the laser emitter and the collimator iscorrespond to a relative position between the laser emitter and thecollimator model.

Preferably, the base is detachably mounted to the irradiation roomand/or the preparation room.

In yet another aspect of the present disclosure provides neutron capturetherapy system, the neutron capture therapy system includes airradiation room configured to irradiate an irradiated body with aneutron beam, and an auxiliary positioner disposed in the irradiationroom, wherein the auxiliary positioner includes a cantilever providedwith at least one laser emitter for emitting a laser beam to positionthe irradiated body. A position of the laser emitter is selectable.

Preferably, the auxiliary positioner further includes a base from whichthe cantilever extends perpendicularly, and wherein the laser emitter isdisposed on the cantilever.

Preferably, the base is detachably mounted on the irradiation room.

Preferably, a collimator is disposed on the irradiation room, theauxiliary positioner is detachably mounted on the collimator.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate one or more embodiments of thedisclosure and together with the written description, serve to explainthe principles of the disclosure. Wherever possible, the same referencenumbers are used throughout the drawings to refer to the same or likeelements of an embodiment.

FIG. 1 is a top view of a neutron capture therapy system according tothe present disclosure;

FIG. 2 is a schematic diagram of an irradiation room installed with apositioning device in FIG. 1 ;

FIG. 3 is a schematic diagram of a preparation room installed with apositioning module in FIG. 1 ;

FIG. 4 is a perspective view of an auxiliary positioner according tofirst embodiment of the present disclosure;

FIG. 5 is a front view of the auxiliary positioner in FIG. 4 ;

FIG. 6 is a perspective view of an auxiliary positioner according tosecond embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a fixing portion corresponding to theauxiliary positioner in first embodiment in an irradiation room;

FIG. 8 is a schematic diagram of a positioning portion corresponding tothe auxiliary positioner in first embodiment in a preparation room;

FIG. 9 is a schematic diagram of a fixing portion corresponding to theauxiliary positioner in second embodiment in an irradiation room; and

FIG. 10 is a schematic diagram of a positioning portion corresponding tothe auxiliary positioner in second embodiment in a preparation room.

DETAILED DESCRIPTION OF THE DISCLOSURE

The embodiments of the present disclosure are further described indetail below with reference to the accompanying drawings, so that thoseskilled in the art can implement the technical solutions according tothe description.

Neutron capture therapy has been increasingly practiced as an effectiveapproach for treating cancer in recent years, and BNCT is the mostcommon. Neutrons for BNCT may be supplied by a nuclear reactors, a D-Tneutron generators, a D-D neutron generators, a spallation neutronsources or accelerators. Take accelerator-based BNCT for example in theembodiments of the present disclosure. Basic components for theaccelerator-based BNCT generally include an accelerator configured toaccelerate a charged particles (such as protons and deuterons, etc.), aneutron generator, a heat removal system, and a beam shaping assembly.The accelerated charged particles react with a metal neutron generatorto generate neutrons. Suitable nuclear reactions are selected accordingto characteristics such as the desired neutron yield and energy, theenergy and the current of the accelerated charged particle, andmaterialization of the metal neutron generator. The most discussednuclear reactions are ⁷Li(p,n)⁷Be and ⁹Be(p,n)⁹B.

As shown in FIG. 1 , a neutron capture therapy system 1 includes aneutron beam generating unit 2 configured to generate a therapeuticneutron beam, an irradiation room 3 configured to irradiate anirradiated body, for example, a patient, with the neutron beam, apreparation room 4 configured to perform preparation work beforeirradiation, a management room 5 configured to implement irradiationcontrol, and an auxiliary positioner 6 configured to auxiliarypositioning of the patient in special occasions.

The neutron beam generating unit 2 is configured to generate the neutronbeam outside the irradiation room 3 and irradiate the patient with theneutron beam. The neutron beam generating unit 2 includes a cyclotron 21configured to accelerate a charged particle beam, a neutron beamgenerator 23 that reacts with the charged particle beam to generate theneutron beam, and a charged particle beam transmitter 22 located betweenthe cyclotron 21 and the neutron beam generator 23 and configured totransmit the charged particle beam. The neutron beam generating unit 2is surrounded by a shielding wall W1 made of concrete. The chargedparticle beam transmitter 22 transmits the charged particle beam to theneutron beam generator 23, one end of the charged particle beamtransmitter 22 is connected to the cyclotron 21, and the other end ofthe charged particle beam transmitter 22 is connected to the neutronbeam generator 23. In other embodiments, other accelerators may be usedin place of the cyclotron. A beam control device such as a beamadjuster, a current monitor, and a charged particle scanner may bedisposed on the charged particle beam transmitter 22 according to anactual requirement. The beam control device controls a direction oftravel and a beam diameter of the charged particle beam. The currentmonitor measures a current value (that is, charge, and a radiation doserate) of the charged particle beam in real time. The charged particlescanner scans the charged particle beam and controls an irradiationposition of the charged particle beam with respect to the neutron beamgenerator 23. The neutron beam generator 23 includes a target T thatreacts with the charged particle beam to generate a neutron beam and abeam shaping assembly 24 that slows down and shields against thegenerated neutron beam. The neutron beam generated in the neutron beamgenerator 23 includes a high-speed neutron beam, an epithermal neutronbeam, a thermal neutron beam, and a gamma ray. Specifically, the beamshaping assembly 24 includes a moderator that can slow down the neutronbeam generated from the target T to an epithermal neutron energy range,a reflector that guides neutrons that deviate from a determined routeback to the moderator to increase the intensity of the epithermalneutron beam, a thermal neutron absorber configured to absorb thermalneutrons to protect superficial a normal tissue from an overdose duringtreatment, and a radiation shield configured to shield against leakedneutrons and photons to reduce a dose to the normal tissue in anon-irradiation area. In one embodiment, the target T is made of lithiummetal, the charged particle beam is accelerated enough to overcome theenergy of the coulomb repulsion of atomic nuclei of the target T, andthe ⁷Li(p,n)⁷Be nuclear reaction occurs between the charged particlebeam and the target T to generate the neutron beam. The nuclear reactionmainly occurs between the epithermal neutron beam and boron that entersa tumor in the body of the patient to exert a therapeutic effect. Thetarget T is disposed outside the shielding wall W1, and the beam shapingassembly 24 is buried in the shielding wall W1 along a travelingdirection of the neutron beam.

Referring to FIG. 2 , the irradiation room 3 includes a shielding wallW2, a ceiling 37, a doorway 35 opened in the shielding wall W2 for apatient to enter or exit, a shielding door D1 for opening and closingthe doorway 35, and a shielded space 30 surrounded by the shielding wallW2, the ceiling 37, and the shielding door D1. The patient is placed inthe shielded space 30 to receive treatment of neutron beam irradiation.The shielding wall W2 includes a first shielding wall 31 adjacent to thebeam shaping assembly 24, a second shielding wall 32 opposite to thefirst shielding wall 31, and a third shielding wall 33 and a fourthshielding wall 34 connected between the first shielding wall 31 and thesecond shielding wall 32 and disposed opposite to each other. A conicalcollimator 36 is disposed on the first shielding wall 31 for emittingthe neutron beam. The neutron beam is emitted from the collimator 36 anddefines a neutron beam axis X. In other embodiments, the collimator 36may be disposed into another shape such as a cylinder, a cuboid andother shapes. The third shielding wall 33 is located on a left side ofthe collimator 36, and the doorway 35 is formed through the thirdshielding wall 33 in a direction perpendicular to the neutron beam axisX. A fixing portion 39 for fixing the auxiliary positioner 6 to thefirst shielding wall 31 is disposed in the first shielding wall 31, andthe fixing portion 39 is disposed around the collimator 36.

Referring to FIG. 3 , the preparation room 4 is a room configured toimplement preparation work required before irradiating the patient Swith the neutron beam N. The preparation work includes fixing thepatient to a treatment table, positioning the tumor of the patient, andcompleting three-dimensional positioning marks. In this embodiment ofthe present disclosure, the preparation room 4 is disposed on a leftside of the irradiation room 3, and the preparation room 4 and theirradiation room 3 are separated by the shielding wall W3. In otherembodiments, the preparation room 4 may be disposed at any orientationof the irradiation room 3. The preparation room 4 includes a first wall41 disposed parallel to the first shielding wall 31, a second wall 42located opposite to the first wall 41, a third wall 43 and a fourth wall44 that are located at two ends of the first wall 41 and the second wall42 and connect the first wall 41 and the second wall 42, respectively,and a top wall 45 located above the first wall 41, the second wall 42,the third wall 43, and the fourth wall 44. The first wall 41 is provideda collimator model 46 having a same structure and size as the collimator36 in the irradiation room 3. The collimator model 46 may bealternatively installed in any wall of the second wall 42, the thirdwall 43, and the fourth wall 44 of the preparation room 4. The fourthwall 44 is provided with an entrance 441 formed through the fourth wall44 in the direction perpendicular to the neutron beam axis X for thepatient to enter and exit and a door 442 for opening or closing theentrance 441. A passage 49 is provided between the entrance 441 of thepreparation room 4 and the doorway 35 of the irradiation room 3 for thepatient to enter the irradiation room 3 from the preparation room 4. Thefirst wall 41, the second wall 42, the third wall 43, the fourth wall44, the top wall 45, and the door 442 surround a closed space 40, andthe patient S undergoes the preparation work before irradiation in theclosed space 40. In this embodiment, the first wall 41, the second wall42, the third wall 43, the fourth wall 44 and the top wall 45 of thepreparation room 4 are normal walls, the space 40 is an unshieldedspace. In other embodiments, the first wall 41, the second wall 42, thethird wall 43, the fourth wall 44 and the top wall 45 of the preparationroom 4 are shielded walls, and the space 40 is a shielded space. Thefirst wall 41 is also provided with a positioning portion 49 for fixingthe auxiliary positioner 6 to the first wall 41, and the positioningportion 49 is disposed around the collimator model 46. The structure andsize of the positioning portion 49 are identical with those of thefixing portion 39 in the irradiation room 3. Moreover, when a center 360of the projection of the collimator 36 on the first shielding wall 31and a center 460 of the projection of the collimator model 46 on thefirst wall 41 are respectively used as reference points, the center 360and the center 460 are centers of circle in this embodiment, and whichis referred to as a collimator center 360 and a collimator model center460, respectively. In this case, a coordinate values of a center of thefixing portion 39 is the same as a coordinate values of a center of thepositioning portion 49. Specifically, the neutron capture therapy systemdefines XYZ coordinates including a Y-axis parallel to the neutron beamaxis X, a Z-axis perpendicular to a ground, and an X-axis orthogonal tothe Y-axis and the Z-axis.

The management room 5 is a room configured to manage the entireprocedure implemented using the neutron capture therapy system 1. Forexample, a manager visually confirms the condition of the preparationwork in the preparation room 4 from inside of the management room 5, themanager operates the control device to control the start and stop of theirradiation of a neutron beam, and the like.

Referring to FIG. 1 and FIG. 2 , to position and precisely irradiate thetumor of the patient S, a positioning system is disposed in both theirradiation room 3 and the preparation room 4. Specifically, the secondshielding wall 32, the third shielding wall 33, the fourth shieldingwall 34, and the ceiling 37 of the irradiation room 3 are respectivelyprovided with positioning devices for positioning of the patient S. Thepositioning device includes a first laser positioner 381 disposed on theceiling 37 and located above the collimator 36, a second laserpositioner 382 disposed on the second shielding wall 32 and located infront of the collimator 36, a third laser positioner 383 disposed on thethird shielding wall 33 and located on the left side of the collimator36, and a fourth laser positioner 384 disposed on the fourth shieldingwall 34 and located on a right side of the collimator 36. The positionsof the first laser positioner 381, the second laser positioner 382, thethird laser positioner 383, and the fourth laser positioner 384 arefixed, that is, the laser beams respectively emitted by the first laserpositioner 381, the second laser positioner 382, the third laserpositioner 383, and the fourth laser positioner 384 for positioning thepatient are uniquely determined in a three-dimensional space.

Referring to FIG. 1 and FIG. 3 , the second wall 42, the third wall 43,the fourth wall 44, and the top wall 45 of the preparation room 4 arerespectively provided with a positioning module for positioning andmarking the tumor of the patient S. The positioning module includes afirst positioner 481 disposed on the top wall 45 and located above thecollimator model 46, a second positioner 482 disposed on the second wall42 and located in front of the collimator model 46, a third positioner483 disposed on the third wall 43 and located on the left side of thecollimator model 46, and a fourth positioner 484 disposed on the fourthwall 44 and located on the right side of the collimator model 46. Thepositions of the first positioner 481, the second positioner 482, thethird positioner 483, and the fourth positioner 484 are fixed, that is,the laser beams respectively emitted by the first positioner 481, thesecond positioner 482, the third positioner 483, and the fourthpositioner 484 for positioning the patient are uniquely determined in athree-dimensional space.

The position relationships between the first positioner 481, the secondpositioner 482, the third positioner 483, and the fourth positioner 484and the collimator model 46 are respectively correspondingly the same asthose between the first laser positioner 381, the second laserpositioner 382, the third laser positioner 383, and the fourth laserpositioner 384 and the collimator 36. Specifically, taking thecollimator center 360 and the collimator model center 460 as thereference points, respectively, the coordinate values of the first laserpositioner 381, the second laser positioner 382, the third laserpositioner 383, and the fourth laser positioner 384 are respectivelycorrespondingly the same as those of the first positioner 481, thesecond positioner 482, the third positioner 483, and the fourthpositioner 484.

In the preparation room 4, the CT imaging combined with the positioningmodule is used to position the tumor of the patient and makethree-dimensional marks on the patient's body surface, and then thepatient S is sent in the irradiation room 3 through the passage 49.After the patient enters the irradiation room 3, the patient ispositioned by the positioning device in the irradiation room 3 and thethree-dimensional marks prepared in advance on the body surface of thepatient, so that a neutron beam aims at the tumor for irradiation.Specific marking methods and positioning methods are techniques wellknown to a person of ordinary skill in the art, details are notdescribed herein.

As shown in FIG. 4 and FIG. 5 , the auxiliary positioner 6 of a firstembodiment of the present disclosure includes a base 61 installed on thefixing portion 39 of the irradiation room 3 or the positioning portion49 of the preparation room 4, a cantilever 62 disposed perpendicular tothe base 61, and four laser emitters 63 fixedly installed on thecantilever 62. The base 61 and the cantilever 62 are both rectangularcuboids, the cantilever 62 extends perpendicularly from a centralposition of the base 61, and the laser emitters 63 is installed on aplane of the cantilever 62 facing the collimator 36 or the collimatormodel 46. As observed in the X-axis direction, in the Y-axis direction,a size of the cantilever 62 is greater than a size of the collimator 36and a size of the collimator model 46. The laser emitters 63 are alllocated outside the collimator 36 and the collimator model 46. The base61 is provided with at least two positioning holes 610 penetrating thebase 61 along the Y-axis direction to fix the base 61 to the firstshielding wall 31 or the first wall 41. The base 61 and the cantilever62 are made of metal or plastic with low activity, and are integrallyformed. The laser emitters 63 are sequentially arranged along the Y-axisdirection at equal intervals from a position close to an end of thecantilever 62 away from the base 61. Because the auxiliary positioner 6has a plurality of laser emitters 63, when one or more laser beams areblocked by an obstacle, another unblocked laser beams can be flexiblyselected for positioning, thereby implementing precise positioning andprecise irradiation.

In other embodiments, the base 61 and the cantilever 62 may beseparately formed and then assembled. The base 61 and the cantilever 6are not limited to rectangular cuboids, but may be other shapes such ashexagonal prisms. A quantity of the laser emitters 63 is any quantitygreater than 1.

In other embodiments, the laser emitter 63 may be disposed to be movablealong the Y-axis direction, correspondingly, the cantilever 62 isprovided with a guiderail for guiding the laser emitters 63 and apositioning member for fixing the laser emitters 63 at a predeterminedposition. In another embodiment, the cantilever 62 can be configured asa telescopic structure, and the position of the laser emitters 63 on theY-axis direction can be adjusted by extending or retracting thecantilever 62. In these two embodiments, because the position of thelaser emitters 63 on the Y-axis direction is adjustable, only one laseremitter 63 is needed to implement precise positioning and preciseirradiation, and at the same time manufacturing costs are reduced.

As shown in FIG. 7 , as observed in the Y-axis direction, the fixingportion 39 and the positioning portion 49 corresponding to the auxiliarypositioner 6 in the first embodiment are two “H”-shaped structure withthe collimator center 360 and the collimator model center 460 as thecenters, respectively. Specifically, the fixing portion 39 includes afirst fixing portion 391 located right above the collimator 36 andarranged parallel to the X-axis direction, a second fixing portion 392located on the left side of the collimator 36 and arranged parallel tothe Z-axis direction, and a third fixing portion 393 located on theright side of the collimator 36 and arranged parallel to the Z-axisdirection. The first fixing portion 391, the second fixing portion 392,and the third fixing portion 393 are buried in the first shielding wall31. As observed in the Y-axis direction, the first fixing portion 391,the second fixing portion 392, and the third fixing portion 393 arethree rectangles connected head to tail, and the first fixing portion391, the second fixing portion 392, and the third fixing portion 393form a “H” shape disposed around the collimator center 360. The firstfixing portion 391, the second fixing portion 392, and the third fixingportion 393 are respectively provided with at least two fixing holes 390for fixing the base 61. The fixing holes 390 and the positioning holes610 of the base 61 are threaded holes, the base 61 is fixed on the firstfixing portion 391, the second fixing portion 392, and the third fixingportion 393 via screws to form a detachable fixed connection. In otherembodiments, the base 61 and the first fixing portion 391, the secondfixing portion 392, and the third fixing portion 393 may be fixedtogether in a manner such as a snap-fit through a groove and aprotrusion or magnetic attraction to form a detachable fixed connection.

As shown in FIG. 8 , the positioning portion 49 includes a firstpositioning portion 491, a second positioning portion 492, and a thirdpositioning portion 493 and at least two fixing holes 490 respectivelyprovided in the first positioning portion 491, the second positioningportion 492, and the third positioning portion 493 for fixing the base61. Because the fixing portion 39 and the positioning portion 49 havecorrespondingly the same structure, size, and coordinate values ofcenters when the collimator center 360 and the collimator model center460 are respectively used as reference points, only the fixing portion39 is described in detail herein. For the structure of the positioningportion 49 and the position relationship between the positioning portion49 and the collimator model 46, refer to the foregoing description ofthe structure and size of the fixing portion 39 and the positionrelationship between the positioning portion 49 and the collimator 36.

One or more auxiliary positioners 6 can be installed on the first fixingportion 391, the second fixing portion 392, the third fixing portion393, the first positioning portion 491, the second positioning portion492, or the third positioning portion 493 to replace one or more laseremitters of the first laser positioner 381, the third laser positioner383, and the fourth laser positioner 384 in the irradiation room 3 andthe first positioner 481, the third positioner 483, and the fourthpositioner 484 in the preparation room 4 to position the irradiatedbody.

In other embodiments, the fixing portion 39 and the positioning portion49 may be disposed on the collimator 36, the collimator model 46 orother wall surfaces of the irradiation room 3 and the preparation room4, respectively. Correspondingly, precise positioning can be similarlyimplemented by adjusting the structure of the auxiliary positioner 6.

As shown in FIG. 6 , an auxiliary positioner 6′ of a second embodimentof the present disclosure includes a base 61′ installed on a fixingportion 39′ or a positioning portion 49′, a cantilever 62′ installed onthe base 61′, and a laser emitting device 63′ installed on thecantilever 62′. The cantilever 62′ is provided with a guiderail 624′ forguiding the laser emitting device 63′ to move along the Y-axisdirection. The laser emitting device 63′ includes a sliding member 631′that can slide on the guiderail 624′, a laser emitters 632′ installed onthe sliding member 631′, and a locking member 634′ that fixes thesliding member 631′ on the guiderail 624′. The base 61′ is a hollowcylinder, the cantilever 62′ is a hexahedron having an isoscelestrapezoidal cross section in a direction perpendicular to the Y-axisdirection, and the laser emitters 63′ are installed on the guiderail624′ of the cantilever 62′ facing the collimator 36 or the collimatormodel 46. The guiderail 624′ is a rectangular cuboid parallel to theY-axis direction, and the sliding member 631′ spans the guiderail 624′.The locking member 634′ selectively locks the sliding member 631′ at aposition of the guiderail 624′. The base 61′ is provided with at leasttwo positioning holes 610′ for fixing the base 61′ to the firstshielding wall 31 and the first wall 41. In the Y-axis direction, thesize of the cantilever 62′ is greater than the sizes of the collimator36 and the collimator model 46. That is, the cantilever 62′ protrudesfrom the collimator 36 and the collimator model 46. The laser emitters63′ are all located outside the collimator 36 and the collimator model46. The bases 61′ is provided with an annular track (not shown) for thecantilever 62′ to slide in a circumferential direction and a fasteningmember (not shown) for fixing the cantilever 62′ at a predeterminedposition. Correspondingly, the cantilever 62′ is provided with a guidingportion (not shown) fitting with the annular track and a clamping member(not shown) fitting with the fastening member to fix the cantilever 62′.The guiderail and a guiding member are common forms such as a fit of agroove and a protrusion, and the fastening member and the clampingmember are common locking devices, for example, a fit of an elastic bodyand a groove, and a fit of a bolt and a threaded hole. The bases 61′ andthe cantilever 62′ are made of metal or plastic with low activity. Inthis embodiment, two cantilevers 62′ are installed on the bases 61′, andtwo laser emitting devices 63′ are disposed on each cantilever 62′.According to actual requirement, one to three cantilever 62′ may beinstalled on the bases 61′, and the quantity of the laser emittingdevices 63′ is greater than or equal to 1. Because the laser emitters63′ may move along the guiderail 624′ in the Y-axis direction and may bepositioned at any predetermined position, when an obstacle blocks alaser beam, the position of the laser emitting device 63′ may beflexibly adjusted until the laser beam is not blocked, therebyimplementing precise positioning and precise irradiation.

In other embodiments, a plurality of laser emitting devices 63′ may bedisposed, and the plurality of laser emitting devices 63′ aresequentially arranged in the Y-axis direction at equal intervals from aposition close to an end, away from the base 61′, of the cantilever 62′and are fixedly installed. Because a plurality of laser emitting devices63′ are disposed, when an obstacle blocks one or more of the laserbeams, another unblocked laser beam may be flexibly selected to performpositioning, thereby implementing precise positioning and preciseirradiation. The cantilevers 62′ may be disposed to be fixedly installedon the bases 61′. The cantilevers 62′ may be disposed to be telescopic,and the telescopic cantilevers 62′ are adjusted to adjust the positionsof the laser emitters 63′ in the Y-axis direction. Because the positionof the laser emitting device 63′ in the Y-axis direction is adjustable,only one laser emitting device 63′ needs to be disposed to implementprecise positioning and precise irradiation, and at the same timemanufacturing costs are reduced.

As shown in FIG. 9 and FIG. 10 , as observed in the Y-axis direction,the fixing portion 39′ and the positioning portion 49′ corresponding tothe auxiliary positioner 6′ in the second embodiment are two circularrings with the collimator center 360 and the collimator model center 460as the centers, respectively. The fixing portion 39′ and the positioningportion 49′ has the same size, and respectively surround the collimator36 and the collimator model 46 and are buried in the first shieldingwall 31 and the first wall 41, respectively. The fixing portion 39′ andthe positioning portion 49′ are respectively provided with at least twofixing holes 390′, 490′ for fixing the base 61′. The fixing holes 390′,490′ and the positioning holes 610′ are threaded holes. The base 61′ isfixed to the fixing portion 39′ and the positioning portion 49′ viascrews to form a detachable fixed connection. In other embodiments, thebases 61′ may be fixed together with the fixing portion 39′ and thepositioning portion 49′ in a manner such as a fastening fit of a grooveand a protrusion or magnetic attraction to form a detachable fixedconnection.

One or more cantilevers 62′ on the auxiliary positioner 6′ may bepositioned at corresponding positions to replace one or more laseremitters of the first laser positioner 381, third laser positioner 383,and fourth laser positioner 384 in the irradiation room 3 and the firstpositioner 481, the third positioner 483, and the fourth positioner 484of the preparation room 4 to position the irradiated body.

In other embodiments, the fixing portion 39′ and the positioning portion49′ may be disposed on the collimator 36, the collimator model 46 orother wall surfaces of the irradiation room 3 and the preparation room4, respectively. Correspondingly, precise positioning can be similarlyimplemented by adaptively adjusting the structure of the auxiliarypositioner 6′.

The auxiliary positioner 6, 6′ can be used to replace any one or morelaser positioners of the first laser positioner 381, the third laserpositioner 383, and the fourth laser positioner 384 in the irradiationroom 3 and the first positioned 481, the third positioned 483, and thefourth positioned 484 in the preparation room 4 to position the patient,and the quantity of laser positioners that need to be replaced isdetermined according to an actual case. In actual application, in thepreparation room 4 and the irradiation room 3, when a light beam emittedby one or more laser positioners fixed installed on the wall and ceilingis blocked and positioning cannot be implemented, the auxiliarypositioner 6, 6′ is installed at the corresponding fixing portions 39,39′ and positioning portion 49, 49′ to replace the one or more laserpositioners to implement positioning. A same group of auxiliarypositioners 6, 6′ may be used in the preparation room 4 and theirradiation room 3. That is, after the tumor of the patient S ispositioned and marked in the preparation room 4, the one or moreauxiliary positioners 6, 6′ are detached and installed in theirradiation room 3 for subsequent use. Alternatively, a requiredquantity of auxiliary positioners 6, 6′ may be installed in both thepreparation room 4 and the irradiation room 3, and it is not necessaryto detach the auxiliary positioner 6, 6′ in the preparation room 4 forreuse in the irradiation room 3.

The neutron capture therapy system disclosed in the present disclosureis not limited to the content in the foregoing embodiments and thestructures represented in the accompanying drawings. All obviouschanges, replacements or modifications made to the materials, shapes,and positions of the members based on the present disclosure fall withinthe protection scope of the present disclosure.

Although the illustrative embodiments of the present invention have beendescribed above in order to enable those skilled in the art tounderstand the present invention, it should be understood that thepresent invention is not to be limited the scope of the embodiments. Forthose skilled in the art, as long as various changes are within thespirit and scope as defined in the present invention and the appendedclaims, these changes are obvious and within the scope of protectionclaimed by the present invention.

What is claimed is:
 1. A neutron capture therapy system, comprising: anirradiation room configured to irradiate an irradiated body with aneutron beam, wherein the irradiation room comprises a first shieldingwall and a collimator disposed on the first shielding wall for emittingthe neutron beam, and wherein the neutron beam is emitted from thecollimator and defines a neutron beam axis, a preparation roomconfigured to implement preparation work required to irradiate theirradiated body with the neutron beam, and an auxiliary positionerdisposed in the irradiation room, wherein the auxiliary positionercomprises a laser emitter for emitting a laser beam to position theirradiated body, the auxiliary positioner is disposed around thecollimator and mounted on the first shielding wall or the collimator,and wherein a position of the laser emitter is selectable.
 2. Theneutron capture therapy system according to claim 1, wherein theauxiliary positioner comprises a base and a cantilever extendingperpendicularly from the base, and the laser emitter is disposed on thecantilever.
 3. The neutron capture therapy system according to claim 2,wherein the cantilever is provided with a guiderail for guiding thelaser emitter to move and a positioning member for fixing the laseremitter at a predetermined position.
 4. The neutron capture therapysystem according to claim 2, wherein the cantilever is telescopic. 5.The neutron capture therapy system according to claim 2, wherein aplurality of laser emitters is disposed, the cantilever has an endlocated away from the base, and the plurality of laser emitters aresequentially arranged at intervals from a position close to the end ofthe cantilever being located away from the base.
 6. The neutron capturetherapy system according to claim 2, wherein the preparation roomcomprises a first wall provided with a collimator model corresponding tothe collimator, and the auxiliary positioner is disposed around thecollimator and the collimator model and installed on the first shieldingwall and the first wall.
 7. The neutron capture therapy system accordingto claim 1, wherein the preparation room comprises a first wall providedwith a collimator model corresponding to the collimator, and theauxiliary positioner is installed on the collimator and the collimatormodel.
 8. The neutron capture therapy system according to claim 1,further comprising a neutron beam generating unit for generating theneutron beam, wherein the neutron beam generating unit comprises anaccelerator configured to accelerate a charged particle beam, a neutronbeam generator reacting with the charged particle beam to generate theneutron beam, and a charged particle beam transmitter located betweenthe accelerator and the neutron beam generator and configured totransmit the charged particle beam.
 9. The neutron capture therapysystem according to claim 6, wherein the base and the cantilever areboth rectangular cuboids, the first shielding wall and the first wallare respectively provided with a fixing portion and a positioningportion which are respectively disposed around the collimator and thecollimator model and adapted to fix the auxiliary positioner, whereinthe neutron capture therapy system defines XYZ coordinates including aY-axis parallel to the neutron beam axis, a Z-axis perpendicular to aground, and an X-axis orthogonal to the Y-axis and the Z-axis, thefixing portion comprising a first fixing portion located right above thecollimator and arranged in parallel to the X-axis, a second fixingportion located on a left side of the collimator and arranged inparallel to the Z-axis, and a third fixing portion located on a rightside of the collimator and arranged parallel to the Z-axis, thepositioning portion comprising a first positioning portion, a secondpositioning portion, and a third positioning portion respectivelydisposed corresponding to the first fixing portion, the second fixingportion, and the third fixing portion, wherein a center of a projectionof the collimator on the first shielding wall and a center of aprojection of the collimator model on the first wall are respectivelyconfigured to be reference points, and wherein coordinate values of acenter of the first fixing portion, the second fixing portion and thethird fixing portion based on the reference points are respectively thesame as coordinate values of a center of the first positioning portion,the second positioning portion and the third positioning portion basedon the reference points.
 10. The neutron capture therapy systemaccording to claim 6, wherein the base is a hollow cylinder, thecantilever is a hexahedron disposed perpendicular to the base, the firstshielding wall and the first wall are respectively provided with afixing portion and a positioning portion for fixing the auxiliarypositioner, wherein the neutron capture therapy system defines XYZcoordinates including a Y-axis parallel to the neutron beam axis, aZ-axis perpendicular to a ground, and an X-axis orthogonal to the Y-axisand the Z-axis, and the fixing portion and the positioning portion arehollow circular rings having an identical size and a center of a circlerespectively the same as a center of a projection of the collimator onthe first shielding wall and a center of a projection of the collimatormodel on the first wall.
 11. The neutron capture therapy systemaccording to claim 10, wherein the base is provided with an annulartrack on which the cantilever slides in a circumferential direction anda fastening member for fixing the cantilever at a predeterminedposition, and the cantilever is provided with a guiding portion fittingwith the annular track and a clamping member fitting with the fasteningmember to fix the cantilever.
 12. The neutron capture therapy systemaccording to claim 6, wherein the base is detachably mounted on thefirst shielding wall and the first wall.
 13. The neutron capture therapysystem according to claim 7, wherein the base is detachably mounted onthe collimator and the collimator model.
 14. A neutron capture therapysystem, comprising: an irradiation room provided with a collimator for aneutron beam to be emitted, a preparation room provided with acollimator model corresponding to the collimator, and an auxiliarypositioner disposed in the irradiation room and/or the preparation room,wherein the auxiliary positioner comprises a base and a cantileverextending from the base, and wherein the cantilever is provided with atleast one laser emitter for emitting a laser beam, wherein a position ofthe at least one laser emitter is selectable, and a relative positionbetween the at least one laser emitter and the collimator corresponds toa relative position between the at least one laser emitter and thecollimator model.
 15. The neutron capture therapy system according toclaim 14, wherein the base is detachably mounted to the irradiation roomand/or the preparation room.
 16. A neutron capture therapy system,comprising: an irradiation room configured to irradiate an irradiatedbody with a neutron beam, wherein the irradiation room comprises a firstshielding wall, and an auxiliary positioner disposed in the irradiationroom, wherein the auxiliary positioner includes a cantilever providedwith at least one laser emitter for emitting a laser beam to positionthe irradiated body, wherein a collimator is disposed on the firstshielding wall, and the auxiliary positioner is detachably mounted onthe first shielding wall or the collimator, and wherein a position ofthe at least one laser emitter is selectable.
 17. The neutron capturetherapy system according to claim 16, wherein the auxiliary positionerfurther comprises a base from which the cantilever extendsperpendicularly, and wherein the laser emitter is disposed on thecantilever.
 18. The neutron capture therapy system according to claim17, wherein the base is detachably mounted on the irradiation room.